• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.6
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• pp.71-80
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• 1994

The purpose of this paper is to explore the use of fuzzy set theory for image processing and analysis. As an application example, the fuzzy method of edge detection is proposed to extract the edges of raised characters on tires.In general, Sobel, Prewitt, Robert and LoG filters are used to detect the edge, but it is difficult to detect the edge because of ambiguity of representations, noise and general problems in the interpretation of tire image. Therefore, in his paper, the fuzzy property plane has been extracted from the spatial domain using the ramp-mapping function. And then the ideas of fuzzy MIN and MAX are applied in removing noise and enhancement of the image simultaneously. From the result of MIN and MAX procedure a new fuzzy singleton is generated by extracting the difference between adjacent membership function values. And the edges are extracted by applying fuzzy $\alpha$-cut set to the fuzzy singletion, Finally, these ideas are applied to the tire images.

• Journal of Communications and Networks
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• v.9 no.2
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• pp.185-191
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• 2007

Alpha stable distribution is better for modeling impulsive noises than Gaussian distribution in signal processing. This class of process has no closed form of probability density function and finite second order moments. In general, Wiener filter theory is not meaningful in S$\alpha$SG environments because the expectations may be unbounded. We proposed a new adaptive recursive least p-norm Kalman filtering algorithm based on least p-norm of innovation process with infinite variances, and a new robust multiuser detection method based on least p-norm Kalman filtering. The simulation experiments show that the proposed new algorithm is more robust than the conventional Kalman filtering multiuser detection algorithm.

• Nuclear Engineering and Technology
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• v.14 no.1
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• pp.10-16
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• 1982

The significant structure theory of liquids has been successfully applied to liquid gallium. In this work, we have assumed that two structures exist simultaneously in liquid gallium. One is considered as loosely close packed $\beta$-Ga-like structure and the other is the remainder of solid $\alpha$-Ga or $\alpha$-Ga-like structure. This two structural model is introduced to construct the liquid partition function. Using the partition function, the thermodynamic and transport properties are calculated over a wide temperature range. The calculated results are quite satisfactory when compared with the experimental results.

• Communications of the Korean Mathematical Society
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• v.39 no.2
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• pp.373-397
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• 2024

Lambek introduced the concept of symmetric rings to expand the commutative ideal theory to noncommutative rings. In this study, we propose an extension of symmetric rings called strongly α-symmetric rings, which serves as both a generalization of strongly symmetric rings and an extension of symmetric rings. We define a ring R as strongly α-symmetric if the skew polynomial ring R[x; α] is symmetric. Consequently, we provide proofs for previously established outcomes regarding symmetric and strongly symmetric rings, directly derived from the results we have obtained. Furthermore, we explore various properties and extensions of strongly α-symmetric rings.

• Nonlinear Functional Analysis and Applications
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• v.29 no.2
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• pp.461-475
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• 2024

The concept of an extension α-F-contraction and it's modified counterpart represents an advancement in the theory of metric space contractions. Through our study of the contraction principles and it's relationship to extension and modified extension, we found different conditions somewhat lengthy. In our paper, we create a development of the conditions for the extension of α-F-contraction and a modified α-F-contraction by reducing the conditions and make them easier. Our propose conditions are notably simple and effective. They serve as the foundation for proving theorems and solving examples that belong to our study. Moreover, they have remarkable significance in the condition of mathematical analysis and problem-solving. Thus, we find that these new conditions that we mention in the definitions achieve what is require and through them, we choose λ = 1 and we choose λ ∈ (0, 1) to clarify our ideas.

• Polymer(Korea)
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• v.36 no.3
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• pp.281-286
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• 2012

Experimental study was performed regarding the effects of disc-like filler orientation and contents on the coefficient of thermal expansion (CTE) of polypropylene composites using the three dimensional ellipsoids ($a_1$ > $a_2$ > $a_3$) analyzed by two aspect ratios(${\rho}_{\alpha}=a_1/a_3$and ${\rho}_{\beta}=a_1/a_2$). Measured data were compared with the theoretical approaches proposed by Lee et al. Mica and talc were useed as disk-like fillers in the composites. As experimental results, ${\alpha}_{11}/{\alpha}_m$ decreased down to ca. 0.56 with mica content of 20 wt% and the aspect ratios, ${\rho}_{\alpha}=13.5$, ${\rho}_{\beta}=1.8$. However, ${\alpha}_{33}/{\alpha}_m$ increased to more than 1. In the case of talc, ${\alpha}_{11}/{\alpha}_m$ decreased to ca. 0.63 with 20 wt% and ${\rho}_{\alpha}=3.7$, ${\rho}_{\beta}=1.4$. Finally, the longitudinal CTEs (${\alpha}_{11}$) of polypropylene composites decreased as filler contents increased, but normal CTE (${\alpha}_{33}$) increased in the low filler contents like the theory.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.91-94
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• 2003

본 논문에서는 사용자에게 보다 적합하고 유용한 정보를 제공할 수 있도록 퍼지 $\alpha$-cut을 이용하여 웹 페이지를 부분적으로 표시할 수 있는 방법을 제안한다. 또한, 사용자의 취향과 패턴을 분석하여, 블록화 되어있는 태그들을 중요도에 따라 나타낼 수 있도록 함으로서 사용자의 정보검색에 소요되는 시간과 비용을 절감할 수 있을 것으로 기대된다.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.3
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• pp.205-215
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• 2004

The characteristic ratio assignment (CRA) method〔1〕 is new polynomial approach which allows to directly address the transient responses such as overshoot and speed of response time in time domain specifications. The method is based on the relationships between time response and characteristic ratios($\alpha_i$ ) and generalized time constant (T), which are defined in terms of coefficients of characteristic polynomial. However, even though the CRA can apply to developing a linear controller that meets good transient responses, there are still some fundamental questions to be explored. For the purpose of this, we have analyzed several sensitivities of a linear system with respect to the changes of coefficients itself and $\alpha_i$ of denominator polynomial. They are (i) the unnormalized root sensitivity : to determine how the poles change as $\alpha_i$ changes, and (ii) the function sensitivity to determine the sensitivity of step response to the change of o, and to analyze the sensitivity of frequency response as o, changes. As an other important result, it is shown that, under any fixed T and coefficient of the lowest order of s in denominator, the step response is dominantly affected merely by $\alpha_1, alpha_2 and alpha_3$ regardless of the order of denominator higher than 4. This means that the rest of the$\alpha_i$ s have little effect on the step response. These results provide some useful insight and background theory when we select $\alpha_i$ and T to compose a reference model, and in particular when we design a low order controllers such as PID controller.

• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.1-6
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• 1982

The addition of thiophenol to ${\alpha}$-methylstyrene has been studied MO theoretically using CNDO/2 method. Although overall reaction proceeds in two steps i.e., (1) decomposition of thiophenol to give phenylthiyl radical and (2) addition of the radical to ${\alpha}$-methylstyrene to give a new monomer radical, theoretical results suggested that the phenylthiyl radical formation step, (1), was the dominant process in determining the rate of addition; this was the rationale behind the negative ${\rho}$ value obtained experimentally from the Hammett plots for substituents on the thiyl radicals. The departure from a linear Hammett plot for addition of ${\rho}$-chlorophenylthiyl and m-trifluoromethyl phenylthiyl to ${\rho}$-methoxy-${\alpha}$-methylstyrene could be explained as a result of an increased contribution of the addition step, (2) to the overall reaction rate.

• Journal of Korean Public Health Nursing
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• v.28 no.1
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• pp.57-70
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• 2014

Purpose: This study is a methodological research study for development of a tool for measurement of care satisfaction of home health nursing in patients who have received care through home health nursing and to test the validity and reliability of the tool. Method: Based on Watson's theory of caring and its constituent factors, the literature related to home health nursing was reviewed, and the standard of home health nursing was compared and analyzed. For verification of the validation and reliability of the final tool which has been developed, data were collected from 166 people who were receiving home health nursing care. Result: According to results of analysis of the factors based on Kaiser and scree test, 10 factors with an eigenvalue greater than 1.0 were extracted, and they explained 72.26% of the total variance. In addition, the factor loadings of 56 questions were greater than .30. For verification of reliability, Cronbach's alpha for all 56 items was .98 and Guttman split half reliability coefficient was .90. Conclusion: This tool based on Watson's theory of caring contributed to development and application of the nursing theory through verification of the theory.